NASA太空卫星图上的神秘光点系渔船

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A map of the Earth, released by Nasa last year, revealed something fishy going on off the coast of Argentina.

Around 300 miles offshore, a city of lights was appearing in the middle of the South Atlantic Ocean.

The strange lights were perplexing as there are no humans, fires or gas wells in that region.

What is there however, according to Nasa, are fishing boats with lights powerful enough to be seen in space.

The lights were spotted using Visible Infrared Imaging Radiometer Suite on the Suomi NPP satellite.

According to Nasa, the night fishermen are hunting for Illex argentinus, a species of short-finned squid.

The squid are found tens to hundreds of kilometres offshore from roughly Rio de Janeiro to Tierra del Fuego.

They live 80 to 600 meters below the surface, feeding on shrimp, crabs, and fish.

‘In turn, Illex are consumed by larger finfish, whales, seals, sea birds, penguins ... and humans,’ said Nasa.

Scientists first noted such night-lighting of the seas in the late 1970s and early 1980s, while compiling the first maps of the Earth at night.

‘Squid aggregate in high concentrations at the shelfbreak because it is a very productive area during austral spring and summer,’ explained Marina Marrari, a biological oceanographer with Argentina’s Servicio de Hidrografia Naval.

At the shelfbreak front, microscopic plant-like organisms explode in population in various seasons.

This ‘grass of the sea’ feeds zooplankton and fish, which then become food for Illex argentinus and other marine creatures.

To draw the plankton and fish that the squid eat to the surface, fishermen use powerful lights, generating as much as 300 kilowatts per boat.

Squid follow their prey toward the surface, where they are easier for fishermen to catch with jigging lines.

For many squid, the zooplankton and fish they follow is the last meal they will eat.

In the South Atlantic, Argentine and Falklands citizens have exclusive rights to fish out to 200 miles.

As the map suggests, ships from other nations work as close to that border as they can to get a share of the squid fishing.